Background: Underreporting and misclassification of maternal deaths are universal. The purposes of this study were to quantify the level of underestimation of maternal mortality and to analyze possible factors that contribute to underreporting and misclassification of maternal mortality.
Methods: An interview census of all registered deaths that occurred during 1984-1988 in women of reproductive age was undertaken in Taiwan. Pregnancy-related deaths were screened from all collected questionnaires and death certificates by the researchers. The screened pregnancy-related deaths were then reviewed and evaluated by obstetrician-gynecologists; a cause of each death was assigned.
Results: For the five years, on average, the rate of underreporting of maternal mortality is 58.38% and the correct/confirmed rate of classification is 53.28%. Underreported and misclassified maternal deaths are more likely for women aged 20-24, with stillbirth and fetal death, care sought for non-obstetric reasons, care received in private hospitals and clinics, occurrence in the home, certification by non-obstetrician-gynecologists and court doctors, and death from non-obstetric causes.
Conclusions: This study shows the limitations of official vital registration and concludes that dependence on death certificates alone to identify maternal deaths is incomplete and incorrect.
PIP: This study determines the reliability of death certificate information on maternal mortality in Taiwan. A file was constructed of death certificates of all females 10-49 years old who died during 1984-88 in Taiwan. Trained public health nurses and midwives interviewed family members of deceased persons. Cause of death was taken from the death certificate. Obstetricians-gynecologists determined whether a pregnancy-related death was due to obstetric or unrelated causes, according to the International Classification of Disease-9, Clinical Modification codes. Based on the physicians reviews, 520 women died during pregnancy or within 42 days postpartum, of which 246 were nonmaternal deaths. 173 of the 274 deaths were previously determined by the routine procedure of death certificate reporting to be maternal deaths. Obstetrician-gynecologists identified 101 deaths as maternal deaths. 146 of the 173 certificate maternal deaths were verified as maternal deaths. 27 deaths were minor misclassifications. The adjusted proportion of maternal deaths was 54.8% rather than 34.6%. The greatest rate of underreporting was 86.59% in 1988. The smallest rate of underreporting was 39.29% in 1987. The official death certificate maternal group had a significantly higher percentage of women 30-34 years old. The underreported group had a significantly higher percentage of women 20-24 years old. The underreported group had a higher proportion of stillbirths and fetal deaths among mothers who died. The reported group had higher proportions of deaths from hypertension, embolism, hemorrhage, and more mothers who sought care at clinics and hospitals. The misclassified group had more information provided by physicians and family. Underreporting is attributed to confusing coding criteria, neglect of physicians, incomplete information, specific indicators, and avoidance of blame.